The relative lowering of vapour pressure caused by dissolving 71.3 g of a substance in 1000 g of water is 7.13 X 10^-3. The molecular mass of the substance is :-

(1) 180

(2) 18

(3) 1.8

(4) 360

100 g solute is dissolved in 1400 g of solvent. The density of the resultant solution is 1.5g/mL. The ratio of its molarity and molality will be :-

(1) 1.5

(2) 1.3

(3) 1.4

(4) 1.2

When 36 g of a solute having the emperical formula CH₂O is dissolved in 1.2 kg of water, the solution freezes at -0.93$°\mathrm{C}$. What is the molecular formula of solute (K_f=1.86 kg K mol^-1)

(1) C₂H₄O

(2) C₂H₂O₂

(3) C₂H₄O₃

(4) C₂H₄O₂

One litre aqueous solution of sucrose (molar mass = 342 g/mol) weighing 1015 g is found to record an osmotic pressure of 4.8 atm at 293K. What is the molality of the sucrose solution ? (R= 0.0821 L atm K^-1 mol^-1) :

(1) 0.84

(2) 0.21

(3) 0.42

(4) 0.63

What is the vapour pressure of a solution when the mole fraction of water is 0.9, assuming the vapor pressure of pure water is 30 mm Hg at room temperature?

1. 30 mm of Hg

2. 24 mm of Hg

3. 21 mm of Hg

4. 27 mm of Hg

The van't Hoff factor of a 0.005 M aqueous solution of KCl is 1.95. The degree of ionisation of KCl is-

1. 0.95

2. 0.97

3. 0.94

4. 0.96

K₄[Fe(CN)₆] is 60% ionised. Then the value of Van't Hoff factor is

1. 1.6

2. 2.4

3. 3

4. 3.4

In a cold climate frozen causing damage to radiator of a car. Ethylene glycol is used as antifreezing agent. The amount of ethylene glycol to be added to 4 kg of water to prevent it from freezing at $-6°C$. $[k_f<mspace\; width="1em"></mspace>for<mspace\; width="1em"></mspace>water=1.85<mspace\; width="1em"></mspace>k<mspace\; width="1em"></mspace>kg<mspace\; width="1em"></mspace>mo{l}^{-1}]$

1. 204.22 g

2. 804.32 g

3. 602 gm

4. 401 gm

A 0.002 molar solution of NaCl having degree of dissociation of 90% at 27$°\mathrm{C}$, has osmotic pressure equal to :-

(1) 0.94 bar

(2) 9.4 bar

(3) 0.094 bar

(4) 9.4 X 10^-4 bar

Saturated solution of Ag₂SO₄ shows 0.003K rise in boiling point, K_sp will be :(K_b = 5 K kg mol^-1)(1m=1M)

1. 3.2 x 10^-11

2.  3.2 x 10^-10

3.  3.2 x 10^-9

4.  3.2 x 10^-12